Stacked-Plate Heat Exchanger

ABSTRACT

The invention relates to a stacked-plate heat exchanger, particularly an in-tank oil cooler, which is mounted in a coolant casing of a coolant cooler for vehicles. The heat exchanger comprises a number of stacked and interconnected, particularly soldered, elongated plates ( 71 - 77 ), each consisting of two plate halves and enclosing a hollow space though which a medium to be cooled, such as oil, passes in a longitudinal direction of the plates. In order to create a stacked-plate heat exchanger that can be economically produced, each of the plate halves have a multitude of grooves extending from one longitudinal side to the opposite longitudinal side of the plate half.

The invention relates to a stacked-plate heat exchanger, in particular an in-tank oil cooler, for motor vehicles, with a plurality of elongate plates which are stacked one on the other and are connected, in particular soldered, to one another and which are composed in each case of two identical plate halves rotated through 180° with respect to one another and surround a cavity for leading through a medium to be cooled, such as oil, in the longitudinal direction of the plates.

German laid-open publication DE 43 08 858 C2 discloses a plate heat exchanger with plates which are stacked one on the other and are soldered to one another and which are composed of two identical plate halves rotated through 180° with respect to one another and surround a cavity for the conduction of a medium to be cooled. The plate halves are provided with an embossed edge for soldering the plate halves to form a plate and with connection faces for soldering the plates to one another. Moreover, the plate halves are provided on the inside and on the outside with frustoconical embossings. The plate halves are configured mirror-symmetrically with respect to their transverse and/or longitudinal axis. The frustoconical embossings are arranged in the manner of a checkerboard between the connection faces. Positive embossings alternate with negative embossings. The positive embossings and the negative embossings are of knob-like design. In the assembled state, the plate halves surround a cavity through which a fluid, for example oil, flows. The knobs projecting into this cavity are intended to ensure a good swirling of the oil and, as a result of their tie rod function, to increase the strength.

The object of the invention is to provide a stacked-plate heat exchanger, in particular an in-tank oil cooler, for motor vehicles, with a plurality of elongate plates which are stacked one on the other and are connected, in particular soldered, to one another and which are composed in each case of two identical plate halves rotated through 180° with respect to one another and surround a cavity for leading through a medium to be cooled, such as oil, in the longitudinal direction of the plates, which stacked-plate heat exchanger is of simple construction and can be produced cost-effectively. The stacked-plate heat exchanger according to the invention is nevertheless to ensure good swirling of the medium to be cooled in the cavity formed between the plate halves.

In a stacked-plate heat exchanger, in particular an in-tank oil cooler, for motor vehicles, with a plurality of elongate plates which are stacked one on the other and are connected, in particular soldered, to one another and which are composed in each case of two plate halves and surround a cavity for leading through a medium to be cooled, such as oil, in the longitudinal direction of the plates, the object is achieved in that each of the plate halves has a multiplicity of grooves which run from one longitudinal side of the plate half to its opposite longitudinal side. The plates are also designated as flat tubes or panels. The run of the grooves ensures the passage of coolant from one longitudinal side of the plate half to the opposite longitudinal side. In the cavity, the grooves ensure a good swirling of the medium to be cooled.

A preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the elongate plates are composed in each case of two identical plate halves rotated through 180° with respect to one another. The production of the stacked-plate heat exchanger according to the invention is thereby simplified considerably.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves run rectilinearly from one longitudinal side of the plate half to its opposite longitudinal side. This ensures an unimpeded passage of coolant from one longitudinal side of the plate half to the opposite longitudinal side.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves are embossed on one side in each plate half. The grooves are formed by rectilinear, elongate, narrow depressions which are embossed on one side, for example, in a sheet metal material. Since the grooves are embossed on only one side, the production of the plate halves is simplified.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves are delimited on the longitudinal sides by a peripheral edge. The peripheral edge serves for connecting, in particular soldering, two plate halves to one another. The cavity between the two plate halves is thereby sealed off with respect to the surroundings.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that a plate is formed by two plate halves which bear against one another and the grooves of which are embossed outwardly. The grooves delimit, inside the plate, the flow path of the medium to be cooled. Preferably, an inlet for the medium to be cooled is provided at one end of the plate and an outlet for said medium is provided at the other end of the plate.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that two plates bear against one another with their raised regions formed by the grooves and are connected to one another by means of a soldering process. Coolant, for example water, can pass between the raised regions from one longitudinal side of the respective plate half to its opposite longitudinal side. Moreover, the plates are equipped in the edge region of throughholes with cup-shaped raised regions at which the plates are likewise soldered to one another.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves run at an angle of 35° to 55°, in particular of 45°, with respect to the longitudinal axis of the associated plate half. This ensures, on the one hand, that the medium to be cooled can flow from one end of the plate to the other end through the cavity formed inside the plate. On the other hand, the run according to the invention of the grooves also ensures that the coolant can flow in two plates from one longitudinal side to the opposite longitudinal side.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves of two plate halves bearing against one another are arranged at an angle of 70° to 110°, in particular of 90°, with respect to one another. This provides, inside the plates, for the medium to be cooled a flow path which has many changes of direction and vortices. The advantage of this is that boundary layers which form in the cavity during operation are repeatedly broken up. This leads to a greatly diluted heat transition, as compared with a smooth duct without grooves. Thus, when it flows through the cavity, the medium to be cooled is subjected to many changes of direction. By contrast, the coolant can flow, virtually unimpeded and rectilinearly, through the grooves between two plates bearing against one another. The angle of 90° produces a virtually circular soldering meniscus at the connection point of the two grooves. The flow longitudinally and transversally with respect to the main flow direction of the medium to be cooled is thereby influenced identically. The angle is preferably 80° to 100°.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves have a depth of 0.8 to 1.5 mm, in particular of 1.15 mm. This depth has proved to be particularly advantageous within the scope of the present invention. Particularly in the case of fuel coolers, the grooves preferably have a depth of 0.5 mm to 1.5 mm.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the grooves of a plate half are arranged parallel to one another at a distance of 3 to 5 mm, in particular of 4 mm, from one another. This division dimension has proved to be particularly advantageous within the scope of the present invention.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the plate halves have a width of about 20 to 50 mm.

This width has proved to be particularly advantageous within the scope of the present invention. In commercial vehicles, the plate halves preferably have a width of about 20 to 120 mm. A width of 70 to 80 mm, in particular of 76 mm, is particularly preferred.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the hydraulic diameter has a value of 1.5 to 2.5 mm, in particular of 1.8 mm. This value has proved to be particularly advantageous within the scope of the present invention.

The hydraulic diameter between two adjacent plate halves along the main flow direction of the medium to be cooled constitutes the ratio between the throughflow duct cross section and the heat exchange area. The hydraulic diameter is defined as the quadruple of the ratio of the area ratio to the area density. The area ratio is determined as the ratio of the free duct cross section to the overall end face area of the duct between two adjacent plate halves. The area density is determined from the ratio of the heat-transmitting area to the block volume. The hydraulic diameter should preferably remain as constant as possible over the entire main flow direction of the medium to be cooled. A uniform throughflow capacity of the cavity between two plate halves is thereby achieved.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the plate halves are formed from a metallic material, in particular from aluminum or high-grade steel. The plates are preferably connected to one another by hard soldering. High-grade steel is preferably used in commercial vehicles.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that at least one side of the plate halves is coated with soldering aid material. The process of producing the stacked-plate heat exchanger according to the invention can thereby be simplified.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the plate halves have in each case a pair of throughholes as inflow lines and outflow lines. The medium to be cooled passes via the throughholes into the cavity between two plate halves forming a plate or a flat tube. The plates may also be designated as panels and the plate halves as panel halves.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the edge region of the throughholes is of raised design. Preferably, the edge region of the throughholes is raised to exactly the same extent as the grooves or corrugations. Two raised edge regions, bearing against one another, of different plate halves seal off the throughholes and the cavity between two plate halves, which is connected to the throughholes, with respect to the surroundings through which coolant flows.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that embossings are provided in the edge region of the throughholes. The embossings serve for reinforcing the plate halves in the region of the throughholes.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that, as seen in section, the embossings are of wavy design in the inlet region with wave crests and wave troughs.

The wave crests and wave troughs provide essentially punctiform contacts between two adjacent plate halves.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that a plurality of plate halves are soldered in the inlet region essentially linearly to the in each case adjacent plate halves both on their inside and on their outside. The internal pressure resistance of the tubes formed in each case from two plate halves thereby rises sharply.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that, as seen in a top view, the embossings run in a meander-like manner at least partially around the throughholes. The contact area between two plate halves in each case is thereby increased.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that in each case two plate halves are connected to one another in one piece by means of a bending edge running in the longitudinal direction or in the transverse direction, in order to form a conduction device for the medium to be cooled. Since the two plate halves are already connected in one piece to one another at the bending edge, they merely have to be soldered to one another on one side. The cross section through which the medium to be cooled flows is thereby increased. Furthermore, the number of individual parts required is reduced by half, since only one part is required for each conduction device.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the conduction device is formed by an elongate, in particular essentially rectangular, panel which is subdivided by means of the bending edge into two elongate halves which are folded together. The panel is preferably an embossed stamping consisting of a metallic material which can be produced simply and cost-effectively. In the folded-together state, the panel halves lie congruently one on the other.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the panel has a peripheral edge which is raised with respect to the panel surface. Preferably, the panel is embossed within the peripheral edge, the depth of the embossed face amounting to half the clear width of the conduction device.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the peripheral edge is interrupted at the intersection points with the bending edge. In the region of the bending edge, the panel has the same depth over the entire length of the bending edge. This avoids undesirable damage to the panel material in the region of the bending edge during the folding-together operation.

A further preferred exemplary embodiment of the stacked-plate heat exchanger is characterized in that the two panel halves bear against one another with the peripheral edge in the folded-together state. The panel halves are preferably soldered to one another at the peripheral edge.

In a vehicle cooler with at least one waterbox, the object specified above is achieved in that a stacked-plate heat exchanger described above is installed in the waterbox.

Further advantages, features and particulars of the invention may be gathered from the following description in which an exemplary embodiment is described in detail with reference to the drawing. In this case, the features mentioned in the claims and in the description may be essential to the invention in each case individually in themselves or in any desired combination. In the drawing:

FIG. 1 shows a perspective illustration of a plate half;

FIG. 2 shows a bottom view of one end of the plate half from FIG. 1;

FIG. 3 shows a sectional view along the line III-III in FIG. 2;

FIG. 4 shows a perspective illustration of two plate halves;

FIG. 5 shows an enlarged detail from FIG. 4;

FIG. 6 shows a perspective illustration of seven plates which are assembled to form a stacked-plate heat exchanger according to the invention;

FIG. 7 shows an enlarged perspective illustration of a closing-off plate of the stacked-plate heat exchanger illustrated in FIG. 6;

FIG. 8 shows a cross-sectional view through one end of the stacked-plate heat exchanger illustrated in FIG. 6;

FIG. 9 shows a side view of one end of the stacked-plate heat exchanger illustrated in FIG. 6;

FIG. 10 shows a perspective illustration of a waterbox with an installed stacked-plate heat exchanger;

FIG. 11 shows a cooler with an installed waterbox, such as is illustrated in FIG. 10;

FIG. 12 shows an illustration of the soldering menisci in a duct section;

FIG. 13 shows an illustration of a top view of virtually circular soldering menisci;

FIG. 14 shows a top view of a stacked-plate heat exchanger according to a further exemplary embodiment of the invention;

FIG. 15 shows a side view of the stacked-plate heat exchanger from FIG. 14;

FIG. 16 shows a sectional view along the line XVI-XVI in FIG. 14;

FIG. 17 shows a sectional view along the line XVII-XVII in FIG. 14;

FIG. 18 shows a sectional view along the line XVIII-XVIII in FIG. 14;

FIG. 19 shows an enlarged illustration of the detail XIX from FIG. 14;

FIG. 20 shows a top view of a conduction device according to the invention in the folded-open state;

FIG. 21 shows the conduction device from FIG. 20 in the half folded-together state;

FIG. 22 shows a top view of a stacked-plate heat exchanger with a closed conduction device, such as is illustrated in FIGS. 20 and 21, in the closed state;

FIG. 23 shows a side view of the stacked-plate heat exchanger from FIG. 22, and

FIG. 24 shows a sectional view along the line XXIV-XXIV in FIG. 22.

FIG. 1 illustrates a plate half 1 in perspective. The plate half 1 has the configuration of an elongate panel consisting of sheet aluminum with two straight longitudinal sides 2 and 3 which are arranged parallel to one another. The plate half 1 is rounded semicircularly at its ends 4 and 5. Throughholes 8 and 9 are provided in the ends 4 and 5. The edge regions 10, 11 of the throughholes 8, 9 are embossed in a recessed manner, so that the edge regions 10, 11 are raised on the underside of the plate half 1.

A multiplicity of grooves 12 are embossed in the plate half 1 between the throughholes 8 and 9. The grooves 12 run rectilinearly from one longitudinal side 2 of the plate half 1 to its opposite longitudinal side 3. The grooves have the configuration of elongate depressions which are raised on the underside of the plate half 1. However, the grooves may also run nonrectilinearly, for example in a wavy or zigzag-shaped manner.

FIG. 2 illustrates a bottom view of the end 4 of the plate half 1 from FIG. 1. The edge region 10 and ten grooves 21 to 30 are raised out of the drawing plane. The ends of the grooves 21 to 30 are rounded toward the longitudinal sides 2, 3. The longitudinal axis of the plate half 1 is designated by 31. The grooves 21 to 30 are arranged at an angle α of 45° with respect to the longitudinal axis 31.

In FIG. 3, it can be seen that, as seen in cross section, the plate half 1 has a wavy profile. The wavy cross-sectional profile is formed by the grooves which are embossed on one side in the plate half 1.

FIG. 4 illustrates two plate halves 1 and 42 in perspective. The sides of the plate halves 1 and 42 on which the grooves are raised face away from one another.

In FIG. 5, it can be seen that the plate half 42 has exactly the same configuration as the plate half 1.

However, the plate half 42 is arranged so as to be rotated through 180° with respect to the plate half 1. One end 44 with a throughhole 48, the edge region 50 of which is raised out of the drawing plane, is arranged above the throughhole 8 of the end 4 of the plate half 1, the cup-shaped edge region 10 of the throughhole 8 being raised into the drawing plane. Grooves 52 which are raised out of the drawing plane are formed in the plate half 42. The grooves 52 are arranged at an angle β of 90° with respect to the grooves 12 which are raised into the drawing plane. The two plate halves 1 and 42 are soldered to one another at the contact points of the grooves and in the edge regions 2 and 3 so as to form a plate or a flat tube.

In FIG. 6, a multiplicity of plates 60 are soldered to one another. The throughholes of the plates 60 are closed on the underside by means of closing-off plates 61, 62. On the top side of the plates 60, connection pieces 67, 68 are placed onto the throughholes at the ends. The medium to be cooled can be introduced through one of the connection pieces 67, 68 into the interior of the plates 60. The medium to be cooled can emerge from the plates 60 out of the other connection piece 68, 67.

FIG. 7 illustrates the closing-off plate 61 in an enlarged perspective view. The closing-off plate 61 has the configuration of a circular plate 64 which has a circular central elevation 65. The outside diameter of the circular elevation 65 is adapted to the inside diameter of the associated throughhole of the respective plate.

In FIGS. 8 and 9, it can be seen that the stacked-plate heat exchanger illustrated in perspective in FIG. 6 comprises seven plates 71 to 77 which are stacked one above the other. Inside the plates 71 to 77, a multiplicity of essentially zigzag-shaped flow paths for the medium to be cooled are formed, which run between the plates 71 to 77 rectilinearly through the recessed regions in each case between two grooves from one side of the corresponding plate half to its opposite side.

FIG. 10 illustrates a waterbox 78 in which the stacked-plate heat exchanger illustrated in FIG. 6 is installed. The plates 60 are arranged within the waterbox 78. The connection pieces 67, 68 project out of the waterbox 78.

In FIG. 11, the waterbox 78 from FIG. 10 is built onto one side of a cooling network 79. A further waterbox 80 is built onto the other side of the cooling network 79. The two waterboxes 78 and 80 and the cooling network 79 together form a coolant cooler 81 for a motor vehicle (not illustrated).

The profiling of the plate halves 1 and 42 is designed such that the wavy profiles are in punctiform contact with one another when the plates are laid one onto the other. This repeatedly results, inside the plates, in changes of direction for the medium to be cooled which flows through. The multiplicity of contact points at which the two plate halves are soldered to one another ensures good pressure stability. The leg angle of the profiling is 45° with respect to the main flow direction of the medium to be cooled. The hydraulic diameter amounts to 1.8 mm. The embossing angle is in a range of between 20° and 60° with respect to the main flow direction. The hydraulic diameter may vary between 1.5 mm and 2.5 mm.

The large-area embossing in the inlet and outlet region makes it possible to have a leaktight plate connection, without additional components having to be used. The plate halves have horizontal soldering faces, thus ensuring a sufficient flow passage of the coolant on the outside of the cooler. The plate halves are preferably angled slightly at their peripheral edge. The planeness of the plate in the unsoldered state is thereby improved. The edge angle is between 5° and 20°, preferably 10°. The plate halves consist of aluminum and are connected to one another by means of a wheel-soldering process.

In FIG. 12, it can be seen that in each case two plate halves are connected to one another by means of soldering menisci 101, 102 and 103, 104. In FIG. 13, it can be seen that the soldering menisci 101 to 104 are of virtually circular design, as seen in a top view.

FIG. 14 illustrates a plate half 1 of a stacked-plate heat exchanger according to the invention in a further exemplary embodiment. The same reference symbols as in the exemplary embodiment illustrated in FIG. 1 are used to designate identical parts. In order to avoid repetitions, reference is made to the preceding description of FIG. 1. Only the differences between the exemplary embodiments are dealt with below.

In the plate half 1 illustrated in FIG. 14, the edge regions 110, 111 of the throughholes 8, 9 are provided with embossings. The edge region 111 at the end 5 of the plate half 1 has meander-like embossings 115 and 116 which are connected by means of a connecting bead 117. The edge region 110 at the end 4 of the plate half 1 has meander-like embossings 118 and 119 which are connected to one another by means of a connecting bead 120. In each case two plate halves 1, such as are illustrated in FIG. 14, are, as described above, soldered to one another at the contact points of the grooves 12 and in the edge regions 2 and 3 and also at the embossings 118, 119 so as to form a plate or a flat tube which is also designated as a conduction device.

FIG. 15 illustrates a side view of a cooler block which comprises a plurality of flat tubes stacked one above the other.

FIG. 16 illustrates a sectional view along the line XVI-XVI in FIG. 14. In the sectional view, it can be seen that various flat tubes of a cooler block are connected linearly to one another in a stacked type of construction in the region of the meander-like embossings 115, 116 and at the embossings 118, 119.

FIG. 17 illustrates a sectional view along the line XVII-XVII in FIG. 14. In the sectional illustration, it can be seen that the number of essentially linear contact faces is increased as a result of the meander-like embossings 116. The meander-like embossings 116 are also designated as reinforcing beads. It can be seen here how the embossings at the plate end are soldered to one another both on the inside and on the outside of the stacked-plate heat exchanger.

FIG. 18 illustrates a sectional view along the line XVIII-XVIII in FIG. 14. It can be seen here how the embossings 119 at the plate end 4 are soldered to one another both on the inside and on the outside of the stacked-plate heat exchanger.

FIG. 19 shows an enlarged illustration of the detail XIX from FIG. 14. The form of the embossings 118, 119 is designed such that plates stacked one above the other are soldered to one another linearly both on the inside and on the outside. The internal pressure resistance of a tube formed from two plate halves thereby rises sharply. The plate connections are illustrated in a meandering manner in FIG. 19.

FIG. 20 illustrates a conduction device 140, which is also designated as a flat tube or short tube, in the folded-open state. The flat tube 140 is formed by a panel 142 which has essentially the configuration of a rectangle, the corners of which are rounded. The panel 142 is a stamping consisting of sheet aluminum having a bending edge 143, by means of which the panel 142 is subdivided in the longitudinal direction into two halves 145, 146 of identical size which are also designated as plate halves. The two plate halves 145, 146 correspond, apart from their one-piece design, to the plate halves of the preceding exemplary embodiments. The panel 142 is delimited on the outside by a peripheral edge 148 which serves for soldering the two panel halves 145, 146 to one another in the folded-together state. Within the peripheral edge 148, the panel halves 145, 146 are provided with embossed grooves, such as are described above.

FIG. 21 illustrates the tube 140 in the partly closed state.

FIG. 22 illustrates a top view of the tube 140 in the closed state. The tube 140 is the uppermost flat tube of a stacked-plate heat exchanger having a plurality of flat tubes stacked one above the other.

FIG. 23 illustrates a side view of the stacked-plate heat exchanger from FIG. 22. In the side view, it can be seen that the stacked-plate heat exchanger also comprises, in addition to the flat tube 140, six further flat tubes 150 to 155 which are soldered to one another in a stacked type of construction.

FIG. 24 illustrates a sectional view along the line XXIV-XXIV in FIG. 22. In the sectional view, it can be seen that the stacked-plate heat exchanger is formed from folded-together flat tubes 140, 150 to 155. By the flat tubes being produced in one piece, the number of parts necessary for constructing the stacked-plate heat exchanger is reduced to half. The folded flat tubes have the advantage that the length of the sealing solder seam is reduced by virtually half. 

1. A stacked-plate heat exchanger, in particular in-tank oil cooler, which is installed in a coolant box of a coolant cooler, for motor vehicles, with a plurality of elongate plates which are stacked one on the other and are connected, in particular soldered, to one another and which are composed in each case of two plate halves and surround a cavity for leading through a medium to be cooled, such as oil, in the longitudinal direction of the plates, wherein each of the plate halves has a multiplicity of grooves which run from one longitudinal side of the plate half to its opposite longitudinal side.
 2. The stacked-plate heat exchanger as claimed in claim 1, wherein the elongate plates are composed in each case of two identical plate halves rotated through 180° with respect to one another.
 3. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves run rectilinearly from one longitudinal side of the plate half to its opposite longitudinal side.
 4. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves are embossed on one side in each plate half.
 5. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves are delimited on the longitudinal sides by a peripheral edge.
 6. The stacked-plate heat exchanger as claimed in claim 1, wherein a plate is formed by two plate halves which bear against one another and the grooves of which are embossed outwardly.
 7. The stacked-plate heat exchanger as claimed in claim 1, wherein two plates bear against one another and are soldered to one another with their raised regions formed by the grooves.
 8. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves run at an angle of 35° to 55°, in particular of 45°, with respect to the longitudinal axis of the associated plate half.
 9. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves of two plate halves bearing against one another are arranged at an angle of 70° to 110°, in particular of 90°, with respect to one another.
 10. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves have a depth of 0.5 to 1.5 mm, in particular of 1.15 mm.
 11. The stacked-plate heat exchanger as claimed in claim 1, wherein the grooves of a plate half are arranged parallel to one another at a distance of 3 to 5 mm, in particular of 4 mm, from one another.
 12. The stacked-plate heat exchanger as claimed in claim 1, wherein the plate halves have a width of about 20 to 120 mm, in particular of 20 to 50 mm.
 13. The stacked-plate heat exchanger as claimed in claim 1, wherein the hydraulic diameter has a value of 1.5 to 2.5 mm, in particular of 1.8 mm.
 14. The stacked-plate heat exchanger as claimed in claim 1, wherein the plate halves are formed from a metallic material, in particular from aluminum or high-grade steel.
 15. The stacked-plate heat exchanger as claimed in claim 14, wherein at least one side of the plate halves is coated with soldering aid material.
 16. The stacked-plate heat exchanger as claimed in claim 1, wherein the plate halves have in each case a pair of throughholes as inflow lines and outflow lines.
 17. The stacked-plate heat exchanger as claimed in claim 16, characterized in that the edge region of the throughholes is of raised design.
 18. The stacked-plate heat exchanger as claimed in claim 16, wherein embossings are provided in the edge region of the throughholes.
 19. The stacked-plate heat exchanger as claimed in claim 18, wherein, as seen in section, the embossings are of wavy design with wave crests and wave troughs.
 20. The stacked-plate heat exchanger as claimed in claim 19, wherein a plurality of plate halves are soldered essentially linearly to the in each case adjacent plate halves both on their inside and on their outside.
 21. The stacked-plate heat exchanger as claimed in claim 19, wherein, as seen in a top view, the embossings run in a meander-like manner at least partially around the throughholes.
 22. The stacked-plate heat exchanger as claimed in claim 1, wherein in each case two plate halves are connected to one another in one piece by means of a bending edge running in the longitudinal direction or in the transverse direction, in order to form a conduction device for the medium to be cooled.
 23. The stacked-plate heat exchanger as claimed in claim 22, wherein the conduction device is formed by an essentially rectangular panel which is subdivided by means of the bending edge into two elongate halves which are folded together.
 24. The stacked-plate heat exchanger as claimed in claim 23, wherein the panel has a peripheral edge which is raised with respect to the panel surface.
 25. The stacked-plate heat exchanger as claimed in claim 24, wherein the peripheral edge is interrupted at the intersection points with the bending edge.
 26. The stacked-plate heat exchanger as claimed in claim 24, wherein the two panel halves bear against one another with the peripheral edge in the folded-together state.
 27. A motor vehicle cooler with at least one waterbox, wherein a stacked-plate heat exchanger as claimed in claim 1 is installed in the waterbox. 